1. Field of the Invention
The present invention relates generally to crop protection compositions and, in one embodiment, to crop protection compositions containing aryloxyphenoxypropionic esters and uses thereof.
2. Description of Related Art
A wide variety of herbicides are in use today. These known herbicides can be effective against different types of undesirable vegetation and can act in different ways. For example, some herbicides are particularly useful when applied to broad leaf plants while others are more useful when applied to grassy plants. Also, these different herbicides can perform their herbicidal function in different ways. For example, some herbicides may act as acetyl-CoA carboxylase inhibitors while others act in a completely different manner, such asacetolactate synthase inhibitors, or carotenoid biosynthesis inhibitors, or mitosis inhibitors, or photosynthesis inhibitors, just to name a few. In order to combat a wide variety of different types of undesirable vegetation, it is not uncommon to combine several different types of herbicides into a single herbicidal composition. This herbicidal composition can then be applied to a field in a single application without having to apply each of the herbicides individually.
An example of one particularly useful group of herbicides are aryloxyphenoxypropionic esters. Aryloxyphenoxypropionic esters typically act as acetyl-CoA carboxylase inhibitors. An example of such herbicides include fenoxaprop esters, such as fenoxaprop ethyl, commercially available from Bayer CropScience, LP. The fenoxaprop esters, such as fenoxaprop ethyl and fenoxaprop p-ethyl, are particularly useful for application to cereal crops to combat grassy weeds. A basic formula for fenoxaprop herbicides is shown in Formula I below.

The fenoxaprop ester herbicides are quite well adapted for application to cereal crops and have found widespread acceptance. However, it has been observed that when a fenoxaprop ester herbicide, particularly fenoxaprop ethyl, fenoxaprop p-ethyl or a fenoxaprop lower alkyl ester, is mixed with certain other herbicides, the fenoxaprop ester herbicide can degrade more rapidly than if the fenoxaprop herbicide were not mixed with the other herbicides. This has been particularly observed when a fenoxaprop ester is mixed with herbicides that act as weak acids, such as pyrasulfotole and bromoxynil or bromoxynil mixed esters. This increased degradation of fenoxaprop esters can be disadvantageous to a farmer because it can decrease the useful shelf life of a fenoxaprop ester containing herbicidal composition. And while this phenomenon has been discussed with regard to fenoxaprop ester herbicides to illustrate the problem, the problem is not so limited and can occur with many other mixtures of a variety of herbicides. And, as pointed out above, mixing herbicides is often beneficial, as for example to extend the range of weeds, grasses and the like controlled by the herbicidal mixture or the operative times for control, such as to obtain pre- or post-emergent control of the weeds, grasses and the like at various stages in their life cycle.
Therefore, it would be useful to provide herbicidal compositions that reduce or eliminate the drawbacks associated with previous herbicidal compositions, including but not limited to fenoxaprop ester containing herbicidal compositions.